1. Field of the Invention
The present invention relates to computer memory and more specifically to random access read, program, and erase memory.
2. Description of Background
There are two major groups of computer memory, volatile memory and non-volatile memory. In volatile memory constant energy input is required to retain information while in non-volatile memory constant energy input is not required. Examples of volatile memory devices include Dynamic Random Access Memory (DRAM) and Static Random Access Memory (SRAM). DRAM requires the memory element to be constantly refreshed (requiring energy) while SRAM requires a constant supply of energy to maintain the state of the memory element. Examples of non-volatile memory devices are Read Only Memory (ROM), Flash Electrical Erasable Read Only Memory, Ferroelectric Random Access Memory, Magnetic Random Access Memory (MRAM), and Phase Change Memory (PCM). As stated, the information in the memory elements of non-volatile memory can be retained for days to decades without power consumption. The present invention is directed to flash electrical erasable read only memory.
A problem in flash memory is that reading, programming, and erasing operations are carried out in blocks. That is, an entire group of bits in a flash device must be read, programmed, or erased at the same time. This poses problems pertaining to read and write speeds of the flash memory device.